Continuous rolling-mill train, particularly a rod mill

ABSTRACT

A continuous rolling mill, particularly a rod mill, in which the sets of rolls are arranged in two groups in series with one another, with two separate drives, each actuating one group of sets of rolls by means of intermediate gears, the first group of sets of rolls having a definite percentage reduction per pass from one set of rolls to the next, and a pull being exerted upon the stock that is being rolled between the last set of rolls of the first group and the first set of rolls of the second group, and the last set of rolls of the first group being switchable at will into the line of drive of either the first group or the second group, preferably by means of two shifting clutches operable alternatively, interposed between the last set of rolls of the first group and the two driving lines.

United States Patent Inventor Hans-Heinrich Rohde Hosel, Germany Appl. No. 796,323

Filed Feb. 4, I969 Patented July 27, 1971 CONTINUOUS ROLLING-MILL TRAIN,

Primary Examiner-Milton S. Mehr Attorney-Holman and Stern ABSTRACT: A continuous rolling mill, particularly a rod mill, in which the sets of rolls are arranged in two groups in series with one another, with two separate drives, each actuating one group of sets of rolls by means of intermediate gears, the first group of sets of rolls having a definite percentage reduction per pass from one set of rolls to the next, and a pull being exerted upon the stock that is being rolled between the last set of rolls of the first group and the first set of rolls of the second group, and the last set of rolls of the first group being switchable at will into the line of drive of either the first group or the second group, preferably by means of two shifting clutches operable alternatively, interposed between the last set of rolls of the first group and the two driving lines.

PARTICULARLY A ROD MILL 2 Claims, 5 Drawing Figs.

[1.5. CI 72/226, 72/234 lnt.Cl B2lb 1/16 Field of Search 72/226, 249, 234

References Cited UNITED STATES PATENTS 3,153,954 10/1964 Blair 72/234 X 1 l l n- 2 a I 5 6 7 a CONTINUOUS ROLLING-MILL TRAIN, PARTICULARLY A ROD MILL This invention relates to a continuous rolling-mill train, wherein a first group of sets of rolls is driven by one common drive, and a second group of sets of rolls is driven by a further common drive. Between the two groups of sets of rolls, a tensile stress is exerted upon the stock that is being rolled.

According to a suggestion not yet pertaining to the state of the art, the first group of sets of rolls is to be operated with a definite percentage reduction per pass per set of rolls, whereby it is possible, upon the removal from time to time of one or more of the last sets of rolls of the first group, and changing those of the second group, consisting mostly of preoval and finishing passes, to change the rolling program over to a corresponding greater finishing cross section, for which purpose the remaining sets of rolls of the first group are shifted forward in the direction of rolling.

In the effort to obtain the shortest possible changeover times upon the change of program, the stand-still times of the rolling train are to be further shortened.

According to the invention, for this purpose, the last set of rolls of the first group is so constructed that it can be optionally inserted into the line of drive of either the first or the second group.

As a further feature of the invention, a shifting clutch is provided between the driving line of the first group of roll stands and the last set of rolls of the first group, and another shifting clutch between the driving line of the second group and the last set of rolls of the first group. The two shifting clutches can be actuated alternatively.

An advantage of this arrangement is that when the mill train is being changed over from one rolling program to another for the next larger finished cross section, the shifting of the sets of rolls of the first group towards the second group is obviated, and in this way a shortening of the changeover time is ob tained. Such shifting is normally required so as not to increase the distance between the last roll stand of the first group, and the first set of rolls of the second group, as any such increase would alter the tension conditions. Since the roll sets of the first group are fixedly adjusted to a definite cross section of the stock rolled, housing screws are not required therein.

Constructional examples of the invention are illustrated by the accompanying drawings, in which:

FIG. 1 shows in principle the driving of the two groups of roll stands of the rolling train in a known construction; and

FIGS. 2 to 5 show in principle the driving of the two groups of roll stands of the rolling trains in the construction according to the invention, with different rolling programs.

In FIG. 1, 1 denotes a drive for sets of rolls 2 to 9 of a first group ofa wire-rod finishing stage, and 10 denotes a drive for sets of rolls 11 and 12 ofa second group of the wire-rod finishing stage, in the form of construction hitherto adopted. The stock is rolled in the roll line between the sets of rolls 2 to 9 with a uniform percentage reduction per pass, whilst between the sets of rolls 9 and 11 a pull is exerted upon the stock.

Upon the insertion of all the sets of rolls of the first group, the smallest finished cross section that can be rolled upon the train is produced. The changeover to a larger finished cross section is rendered possible by removing one or more of the last sets of rolls of the first group and shifting the remaining sets of rolls towards the end of the first group.

FIG. 2 differs from the known arrangement illustrated in FIG. 1, in that the set of rolls 9 can be driven either by the drive 1 of the first group or by the drive 10 of the second group alternatively, by way of shifting clutches 14, 15.

The advantage of such an arrangement is shown by com paring FIGS. 2 and 3. ln the arrangement according to FIG. 2, with the clutch l4 closed and the clutch 15 open, all the sets of rolls 9 is driven by the drive 1, that is to say, the smallest cross section is being rolled, as in FIG. 1.

FIG. 3, however, a change of program has taken place for the rolling train, for the purpose of now rolling the next larger finished cross section. For this purpose the set of rolls 9 has been removed, and the sets of rolls 11a and 12a of FIG. 2 for the finishing passes are exchanged for fresh sets of rolls 1112 and 12b, which are inserted in the places previously occupied by the sets of rolls 9 and lla, the clutch 14 now being opened and the clutch l5 closed, so that the set of rolls 11b is now driven by the drive 10. It has therefore not been necessary to shift the set of rolls 2 to 8.

The reason for changing the two sets of rolls driven by the drive 10 when a different finished cross section is to be rolled is that these rolls determine the exact form and dimensions of the finished stock, though they do not effect any further reduction in its cross section, They are not designed for pulling the stock through the first group.

For a further change of program, to the next larger finished cross section, as illustrated in FIG. 4, the set of rolls 8 is removed, the sets of rolls 2 to 7 are shifted two places towards the right of the drawings, and the sets of rolls 11b and 12b are replaced by fresh sets of finishing rolls 11c and 120, the clutch 14 being closed and the clutch 15 being opened.

The next change of program involves the removal of the set of rolls 7, the substitution of fresh sets of finishing rolls He and 12a for the sets of rolls 11c and 12s of FIG. 4, the opening of the clutch l4, and the closing of the clutch 15, so that the set of rolls lie is now driven by the drive 10, without any further shifting of the sets of rolls 2 to 6.

In this way, at every alternate changeover, the shifting of the sets of rolls, and with it the stand-still time, can be saved,

1 claim:

1. A continuous train of rolls, particularly a wire-rod rolling train, comprising: sets of rolls, arranged in two groups in series with one another, a first drive for the rolls of the first group, a second drive for the rolls of the second group, the rolls of the first group effecting a definite percentage reduction, per set of rolls, in the cross section of the stock, and the rolls of the second group maintaining the correct finished shape and dimensional tolerance of the stock and also to exert a pull upon the stock issuing from the first group so as to increase the reduction of cross section per set of rolls of the first group, and means for connecting the last roll stand of the first group alternatively at will with either the first drive or the second drive.

2. A continuous rolling mill as claimed in claim I, wherein said last mentioned means includes a shifting clutch interposed between the driving line of the first group of sets of rolls and the last set of rolls of the first group, a second shifting clutch being interposed between the last set of rolls of the first group and the driving line of the second group, and means for opening and closing the two shifting clutches alternatively. 

1. A continuous train of rolls, particularly a wire-rod rolling train, comprising: sets of rolls, arranged in two groups in series with one another, a first drive for the rolls of the first group, a second drive for the rolls of the second group, the rolls of the first group effecting a definite percentage reduction, per set of rolls, in the cross section of the stock, and the rolls of the second group maintaining the correct finished shape and dimensional tolerance of the stock and also to exert a pull upon the stock issuing from the first group so as to increase the reduction of cross section per set of rolls of the first group, and means for connecting the last roll stand of the first group alternatively at will with either the first drive or the second drive.
 2. A continuous rolling mill As claimed in claim 1, wherein said last mentioned means includes a shifting clutch interposed between the driving line of the first group of sets of rolls and the last set of rolls of the first group, a second shifting clutch being interposed between the last set of rolls of the first group and the driving line of the second group, and means for opening and closing the two shifting clutches alternatively. 